Gas turbine



sept. 3o, 1969 SHIGERU lONISHI ETAL GAS TURBINE 2 Sheets-Sheet l FiledMarch 27. 1967 Sept 30, 1969 sHlGERu oNlsHl ETAL 3,469,396

GAS TURBINE Filed March 27, 1967 2 Sheets-Sheet 2 United States Patent O3,469,396 GAS TURBINE Shigeru Onishi, 14-3 Hyotan-cho, Ishikawa-ken,Kanazawa-shi, Japan, and Saburo Yui, 12 3chome Himonya, Meguro-ku,Tokyo, Japan Filed Mar. 27, 1967, Ser. No. 626,146 Claims priority,application Japan, July 2, 1966,

41/ 43,107 Int. Cl. F02c 3/16; F02g 3/00; 1F01d 5/18 U.S. Cl. 60-39.35 3Claims ABSTRACT F THE DISCLSURE A gas prime mover consisting of acompressor, a combustor and a turbine in which the combustor is arrangedand disposed between the rotary members including the compressor and theturbine and the combustor rotates on the sarne axis with the compressorand the turbine.

The present invention relates to a gas prime mover such as a gasturbine, turbojet engine or the like comprising a compressor, combustor,and turbine.

Generally in the prime mover of the type described, atmospheric air iscompressed to a much higher pressure by the compressor, and then suchhighly compressed air is mixed with fuel to be burnt to raise thetemperature of the combustion product to a high temperature. The highlyheated and high pressure gases produced by the combustion of fuel, drivethe turbine to furnish the power, one part of which is used for drivingthe compressor and the remaining part of which is furnished as theeffective output. That is, in the engine of the type there is only aless difference between the Work done when compressed and expanded asthe gas is used. Therefore one of the most important conditions forobtaining the higher effective output is that the efficiencies of thecompressor and the turbine are higher. In order to improve theefficiencies, there have been tried to combine with the major elementconsisting of a compressor, a combustor and a turbine, the regenerator,the inter-cooler, the reheater, and other devices so that the enginesystem may have the higher over-al1 eficiency.

The conventional compressor used with the gas turbine has been designedso as to provide a higher efficiency and to meet the demands for highercompression ratio, higher blade tip speed, and higher Mach number. Thusfor instance, the centrifugal type compressor is conventionally sodesigned that the compressed air leading to the combustor is to beintroduced by the fixed diffuser and the combustor exhaust nozzlediaphragm is provided in order to give to the gases the circumferentialcomponent of the speed equal to the blade tip speed of the turbine whenthe gas is introduced into the turbine from the combustor in the fixedcoordinate. Thus a part of the pressure of the gases are transferred tothe velocity. Especially in case of a centrifugal compressor type gasturbine, the air flow at the outlet of the impeller of the centrifugalcompressor has the resultant of the speed consisting of the blade tipspeed of the impeller and the relative flowing speed in the radialdirection. The major part of the resultant of the speed is the componentof the blade tip speed of the impeller. Thus in order to improve thecompression pressure ratio the blade tip speed must be increased. Atpresent this speed generally exceeds the speed of sound. Therefore thefixed diffuser is playing a major roll, and the dimension of the fixeddiffuser must be large enough for reducing the speed of the supersonicor transonic flow. This leads to the increase of the frontal area of theengine. Further in order to increase the quantity of air flow per unitarea of the front, the air flow must have a Y ice higher velocity. Bythese reasons the adiabatic efficiency is decreased.

The conventional engine of the type described hereinbefore has thedisadvantages or defects in that; when partially loaded, even a slight`change of the attach angle of the flow relative to the fixed diffuserwill cause to lower the eliiciency and also leads to surging due to theflow separation so that the steady state operation cannot be continuedany longer; the combustor is fixed in the fixed coordinate so that thepressure must be converted into the velocity by means of the nozzlediaphragm in order to ow the gases; thus the engine system iscomplicated that vthe air flow must be once converted almost to thestatic pressure by means of the iixed diffuser and then reconverted intothe velocity from the static pressure by means of the nozzle diaphragmafter leaving the combustor so as to have the turbine speed so that thepressure loss will be great, thus preventing the gas temperature at theinlet of the turbine form being elevated and decreasing the turbineoutput; and in order to eliminate such defects described above accessorydevices must be provided so that the engine system becomes morecomplicated, larger in size, and higher in cost.

Bearing in mind the above, the principal object of the present inventionis to eliminate such defects encountered in the conventional engine anddescribed hereinbefore by a simple construction and to provide a gasprime mover which is of practical use and economical.

Another object of the present invention is to eliminate the fixeddiffuser and the turbine nozzle diaphragm which are required in theconventional engine of the type and to simplify the structure of theengine and to make the engine compact in size and light in weight.

Still another object of the present invention is to provide a combustorwithin the rotary member including the compressor and the turbine inorder to arrange and dispose the combustor as the reaction turbine sothat the gas prime mover whose fuel consumption is economical and whichhas a high capacity as Well as high acceleration may be produced at alower cost.

Yet another object of the present invention is to maintain the blade tipspeed obtained in the compressor, in the combustor and then directlyutilize in the power absorbing turbine by integrally constructing thecombustor with the compressor and the turbine into a single assembly sothat the pressure loss may be minimized, the turbine may driveeffectively without being provided with the guide vanes or the like andthe cooling operation may be easily effected without incurring thethermal loss, thus improving the efiiciency.

Further object of the present invention is to provide a gas prime movercompact in size and at a lower cost, which can be operated in a stablestate in the steady state operation with no surging phenomenon due to owseparation at the diffuser when partially loaded, and whose output maybe arbitrarily varied.

The present invention resides in a gas prime mover mainly consisting ofa compressor, a combustor and a turbine characterized in that thecombustor is arranged and disposed within the rotary member includingthe compressor and the turbine; and said combustor is further soarranged and disposed that said combustor may rotate around the sameaxis with those of the compressor and the turbine, whereby the effectiveoutput of the prime mover can be obtained.

Now the invention will be described in detail hereinafter with referenceto the accompanying drawing illustrating one embodiment of the presentinvention wherein:

FIGURE 1 is a sectional view thereof;

FIGURE 2 is a partial side view;

FIGURE 3 is an expanded view of the section at the mean diameter of theturbine blades; and

FIGURE 4 is a sectional view taken along line A-A of FIGURE 1.

Now referring to FIGURE 1, a compresser 1, a combustor 2 and a turbine 3are provided Within a casing 6 having an entrance 4 and an exit 5. Thecombuster 2 is integrally provided with the rotary member including thecompressor 1 and the turbine 3 so that said combustor 2 may rotatearound the same axis with that of the compressor 1 and the turbine 3.

In the ligure, the compressor 1 is of a centrifugal compressorcomprising an impeller 1 of the centrifugal compressor secured to arotary shaft 7 and an outer casing 6 surrounding or enclosing theimpeller 1'. The air is forced to enter the engine from the entrance 4by the centrifugal compressor impeller 1 and then is compressed to ahigher pressure through discharge ports 1 and a bending or slopingportion 8 by the centrifugal force of the impeller 1. The high pressureair thus compressed is then introduced into the rotary combuster 2. (Inthe ow path from the impeller 1 to the bending or sloping portion 8 therelative speed of air flow is decreased while the pressure thereof isincreased.)

An inner combuster 10 provided with suitable holes or openings 9 areprovided in the combustor 2. Fuel injection nozzles 12 are arranged anddisposed in such a manner that the fuel passing through a fuel supplypath 11 within the rotary shaft 7 may be injected into the primarycombustion zone 2'. The jet nozzles 12 are so arranged that fuel may beinjected perpendicularly to the rotary shaft, and the nozzles are spacedpart from one another in the circumferential direction of the shaft. Thefuel which is forcibly injected into the fuel supply path 11 located atthe center of the rotary shaft 7 may have a suicient pressure to atomizeat the injection nozzles 12 by centrifugal force. The fuel injected intothe primary combustion zone 2 is sparked to burn by means of spark plugs13 when the engine is started, and is kept burning continuously byitself without the aid of plugs when once burnt.

As shown in FIGURE 4, the inner tube 10 of the combustor is partitionedfor each of jet nozzles 12, and secondary air is supplied to the shaftside 20 located at the center of the inner combustor 10, and then mixedinto the inner combustor 10, to be utilized as a cooling air at the sametime. The primary combustion chamber 2' is divided into plural rooms bypartition Walls 27. Each roorn faces to fuel injection nozzle 12.Partition walls 27 are provided with holes 28, and adjacent rooms areopened to each other by holes 28. The combustor 2 comprising of theinner combustor 10 is integrally secured to the turbine 3 which issecured to the rotary hollow shaft 7 which is coupled to the impeller 1of the centrifugal compressor and the turbine disk 3' of the turbine 3.The rotary member consisting integrally of the compressor 1, thecombustor 2 and the turbine 3 are mounted in the stationary supportingcasing 6 by means of bearings 24 and 24.

The electricity to be supplied to the spark plugs 13 is supplied fromthe terminal securely fixed to the stationary member of the enginethrough the conductive wire 14 located within the shaft. The conductivewire 14 is insulated (and secured) rigidly at the center of the rotalhollow shaft 7 and the portion of the conductive wire 14 connected tothe terminal 15 is made of a material which has a resistivity againstwear and abrasion and also has a better conductivity. The terminal 15 ispushed forward only when the electricity is supplied in order to sparkthe plugs to start the engine (by means of, for example, anelectromagnetic solenoid 16) and is returned to its initial positionwhen the ignition has been completed.

The turbine 3 is comprising of the turbine disk 3 and the blades 3" andis arranged and disposed as the reaction turbine, which is securely xedto one end of the combustion chamber 2" of the combustor 2 and isrotated therewith at the same speed. Since this turbine 3 is directlyixed to the combustion chamber (shaft side 20'), the turbine disk 3 iscooled by means of the secondary air which is existing in thecombusition chamber 2" and is still cool. The secondary air accumulatesthe heat and is cycled and regenerated partially so that no loss may beproduced. At the opposite side of the turbine disk 3 are provided withsmall diameter holes or openings 17 so as to cool the back face of thedisk 3' and so as to permit the air to flow toward the outer peripheryof the disk 3 and to be discharged outwardly from the root portion ofthe turbine blade 3". The turbine blade 3 is cooled, as indicated inFIGURE 2, by the secondary air introduced directly from the air hole 18provided adjacent to the root portion of the turbine blade 3". Theturbine blade 3" is formed as the cooling blade having a plurality of netubes 19 arranged and disposed within the blade. Thus the turbine blade3 is utilized to elevate the temperature at the entrance of the turbine.

In the figure, the reference numeral 20 designates a guide wallsurrounding or enclosing the combustion chamber 2'; 21 designates holesthrough which the compressed air flow; 22 designates stays in the shapeof an airfoil which are adapted to produce the laminar flow, or tostreamline the iiow; 23 designates a cover body; 25 designates fittingmembers; and 26 designates the extended outer casing of the casing 6.

In FIGURE 3, illustrating the expanded view of the section of the bladeat the mean diameter of the turbine blade, V0 is the circumferentialspeed vector of the turbine blade, V1 is the relative entering velocityvector; and V2 is the relative leaving velocity vector.

Now the starter (not shown) located outside of the engine drives thecompressor 1, and at an appropriate time fuel is injected into thecombustor 2 and is burnt by the ignition devices (spark plugs 13). Thenthe engine is accelerated by increasing the output of the starter andthe quantity of fuel to be injected, so as to increase the output of theturbine 3. When the compressor 1 comes to be driven only by the outputof the turbine 3, the starter is cut off, but the compressor is keptrunning. When the engine is started as described above, the fuel to beinjected is increased so that the engine may be further accelerated andthe load is applied to the engine in order to accomplish the effectivework. Since the engine of the present invention is provided with thecombustion chamber 2 adapted to rotate with the impeller 1 of thecentrifugal compressor, the air ow discharged out of the impeller 1' isdirectly introduced into the combustion chambers 2 and 2" of thecombustor 2. As the combustor 2 is rotated at the same r.p.m. with thatof the impeller 1', the relative ow is only the one leaving radially ofthe impeller 1' and the relative velocity thereof is sufficientlydecreased to a subsonic regime. Furthermore, the air is not positivelycompressed in excess of a certain pressure obtained by decelerating theair flow in the ilow path of the impeller. The substantial part of theiiow velocity is preserved and is introduced into the rotary combustor2. The relative velocity is slow though its absolute velocity is higherso that the highly compressed air is effectively utilized. At the sametime fuel is admixed into the compressed air and burnt in the combustor2 and the high temperature gases produced by the combustion is dilutedby the introduction of the secondary air so that the gas temperaturegradient may be appropriately adjusted (both in the radial andcircumferential directions) and the gases are introduced into theturbine 3. Since the combustor 2 and the turbine 3 are rotating at thesame speed, it is not necessary to convert the pressure of the gasesinto the velocity by the nozzle diaphragm, and now it is possible tomaintain the blade tip speed obtained when entering from the compressorand to be introduced into the power absorbing turbine 3 from thecombustor 2 at the same speed. Since the turbine 3 is a reaction turbinewhich is xedly secured to the combustion chamber 2 and has the samer.p.m. with that of the combustion chamber 2, the direction of the gasesleaving the turbine is opposite relatively to the direction of rotationso that the driving force may be given by its reaction and theefficiency is better. The relative leaving velocity may be used in awide range up to the supersonic regime.

Air Hows from the compressor to the turbine blades in the followingmanner. The air flow from compressor 1 passes between casing 6 and innercombustion 10 to turbine blades 3", and is discharged from exit 5through stays 22. A part of the air owing is pressed into primarycombustion zone 2 through openings 9 in inner combustor and is thendischarged through exit 5 through turbine blades 3. In each chamber 2"or zone 2', air flow passing through openings 9 is controlled by thepressure difference between the inside and the outside of the chamberand the zone. Air flow entering into combustion chamber 2" will furtherenter into shaft side room 20 through holes 21 provided in the guidewall 20, and is thereafter transferred to the side of turbine disc 3.Some part of this air flow is pressed into small diameter holes 17 andair hole 18 and tubes 19 and, in this manner, turbine disc 3 and turbineblades 3 are cooled.

The air entering small diameter holes 17 and air holes 18 will be amixture of air and combustion products entering into shaft side room 20through guide wall 20.

With the arrangement described hereinbefore, the present inventionpermits to eliminate the fixed diffuser and the nozzle diaphragm of theengine which are used in the conventional engine. Thus the engine can bedesigned compact in size and the construction thereof also can besimplified extremely because the compressor has no fixed diffuser.Especially the frontal area of the engine may be reduced. There will beno surging due to the ow separation when partially loaded. The owseparation at the inlpeller is very small so that the continuousoperation of the engine may be made Without any hindrance even when theow separation should take place and so that the acceleration of theengine may be forced in a high-handed way. The adiabatic efficiency ofthe conventional diffuser is generally not so good and is reducedremarkably when partially loaded departing from the design limit. Suchdefect can be eliminated by the present invention with ease and theefficiency may be improved. The output may be varied optionally.Further, the nozzle diaphragm for the turbine may be eliminated so thatthe turbine may be used as the reaction turbine and the eiciency of theturbine itself may be remarkably improved. Since the turbine isintegrated with the combustion chamber, the turbine can contact with thecold secondary air and the turbine blade as well as the turbine disk arecooled in an extremely simple manner thereby to elevate the temperatureat the entrance of the turbine. Thus the specific output and the workratio of the engine may be improved, and the engine of the presentinvention has the advantage in that the engine can be produced compactin size and have a practical flexibility in its use. Since thecompressor, the combustor and the turbine are integrally constructed,the loss due to the leakage of the gases through the gaps and thefriction loss of the rotary disk may be minimized. Other advantages andfeatures of the invention are that the engine having the greatercapacity can be provided simple in construction, compact in size andlight in weight; the engine can be operated in a simple manner; fuelconsumption may be minimized; a high acceleration may be obtained; andthe engine may be operated in a more stable state.

The embodiment has been described with respect to the gas turbine of thetype wherein the output is derived from the shaft thereof. But theturbine may be designed in such a manner that a free turbine is added atthe rear portion of the turbine so as to obtain the power from the freeturbine. Also the engine may be so designed that the rear jet pipe andthe nozzle may be extended so as to form a turbojet engine. In any caseit should be understood that the changes in the arrangement,construction and other related conditions may be made in many waysaccording to the gist and nature of the present invention withoutdeparting from the scope and spirit of the present invention, and thatsuch changes will not limit the scope of the present invention at all.

What we claim is:

1. A gas prime mover comprising a housing having entrant and exit ends,a shaft rotatably mounted in said housing, compressor means carried bysaid shaft proximate to said entrant end, turbine means carried by saidshaft proximate to said exit end, a combustor casing carried by saidshaft intermediate said compressor means and said turbine means, andfuel injection nozzles on said shaft for delivering fuel within saidcombustor casing, said combustor casing including a plurality ofopenings for entry of air from said housing to within said combustorcasing, wherein said combustor casing includes a plurality of partitionsto define a primary combustion zone into which fuel is delivered andmultiple secondary combustion zones, said partions being provided withopenings for communication between said primary and secondary combustionzones.

2. A gas prime mover as claimed in claim 1 wherein said turbine meansincludes a turbine disc and a plurality of turbine blades, saidcombustor casing being provided with a plurality of partition Wallsseparating said blades from said disc, said walls having holestherethrough.

3. A gas prime mover as claimed in claim 1 wherein said turbine meansincludes a plurality of turbine blades, each said blade having aplurality of tubes therewithin communicating with a passage whichcommunicates with said secondary combustion zones.

References Cited UNITED STATES PATENTS 1,960,810 5/1934 Gordon 60-3935XR 2,360,130 10/1944 Heppner 60-39.35 XR 2,404,767 7/ 1946 Heppner60-39.35 XR 2,736,369 2/1958 Hall 60--39.35 XR 2,836,958 6/1958 Ward60-39.35 2,951,340 9/ 1960 Howald. 3,240,016 3/ 1966 Price.

FOREIGN PATENTS 542,461 4/ 1956 Italy.

CARLTON R. CROYLE, Primary Examiner U.S. C1. X.R.

